We’re suspicious of a doctor’s note. Can we challenge its validity?

Are we within our rights to pursue this and require that the employee have the physician complete a more detailed medical certificate?
By Stuart Rudner
|Canadian Employment Law Today

Question:

Our collective agreement requires that an employee “on request from the employer” provide proof of illness or accident from a qualified medical practitioner that is satisfactory to the employer. We recently received from an employee (who has been put on notice, due to her high absenteeism, that she must provide this proof of illness every time she is off sick) a medical note that is somewhat suspect. The date on the note is the same day she returned to work (not the day of illness), the physician’s name at the top of the note has been whited out. There is a stamp of a physicians signature at the bottom, and the “date” of absence due to medical reasons was originally written in as the same date at the top of the note but has been written over to reflect the date of absence.

Are we within our rights to pursue this and require that the employee have the physician complete a more detailed medical certificate? Can a physician “certify” that an employee was absent due to medical reasons on a specific day if he did not see the patient until the next day?